/*
 * The contents of this web application are subject to the Mozilla Public License Version 
 * 1.1 (the "License"); you may not use this web application except in compliance with 
 * the License. You may obtain a copy of the License at http://www.mozilla.org/MPL/.
 * 
 * Software distributed under the License is distributed on an "AS IS" basis, 
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 
 * for the specific language governing rights and limitations under the License.
 * 
 * The Original Code is owned by and the Initial Developer of the Original Code is 
 * Composite A/S (Danish business reg.no. 21744409). All Rights Reserved
 * 
 * Section 11 of the License is EXPRESSLY amended to include a provision stating 
 * that any dispute, including but not limited to disputes related to the enforcement 
 * of the License, to which Composite A/S as owner of the Original Code, as Initial 
 * Developer or in any other role, becomes a part to shall be governed by Danish law 
 * and be initiated before the Copenhagen City Court ("K�benhavns Byret")            
 */

using System;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Linq;
using System.Xml.Xsl;
using Composite.Core.IO;
using Composite.Core.Xml;


namespace Composite.Core.WebClient
{
    /// <exclude />
    [System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Never)] 
	public static class XsltServices
	{
        private static Dictionary<string, XslCompiledTransform> _xsltLookup = new Dictionary<string, XslCompiledTransform>();
        private static Dictionary<string, DateTime> _xsltFileTimestamps = new Dictionary<string, DateTime>();
        private static object _lock = new object();

        /// <exclude />
        public static XslCompiledTransform GetCompiledXsltTransform(string stylesheetPath)
        {
            lock (_lock)
            {
                DateTime lastXsltFileWrite = C1File.GetLastWriteTime(stylesheetPath);

                bool compiledVersionExists = _xsltLookup.ContainsKey(stylesheetPath);
                bool reloadFresh = (DateTime.Now - lastXsltFileWrite).Minutes < 30;

                if (compiledVersionExists == false || lastXsltFileWrite > _xsltFileTimestamps[stylesheetPath] || reloadFresh)
                {
                    XslCompiledTransform xslt = new XslCompiledTransform();
                    using (XmlReader reader = XmlReaderUtils.Create(stylesheetPath))
                    {
                        xslt.Load(reader);
                    }

                    if (compiledVersionExists)
                    {
                        _xsltLookup.Remove(stylesheetPath);
                        _xsltFileTimestamps.Remove(stylesheetPath);
                    }

                    _xsltLookup.Add(stylesheetPath, xslt);
                    _xsltFileTimestamps.Add(stylesheetPath, lastXsltFileWrite);
                }
            }

            return _xsltLookup[stylesheetPath];
        }



        /// <exclude />
        public static XDocument XslTransform(this XDocument sourceDocument, string xsltFilePath)
        {
            XDocument outputDocument = new XDocument();

            XslCompiledTransform xslt = XsltServices.GetCompiledXsltTransform(xsltFilePath);

            using (XmlWriter writer = outputDocument.CreateWriter())
            {
                using (XmlReader reader = sourceDocument.CreateReader())
                {
                    xslt.Transform(reader, writer);
                }
            }

            return outputDocument;
        }
    }
}
